Deal on Lifepo4 aux power solution - Energy Bar 225

[teethless]

Hi All-

I've been weighing my options on how to best power my fridge for short trips, and maybe a year or two ago, someone on the forum turned me on to this product from Aspect Solar. After more back and forth and research, I finally settled onto this Energy bar as how I wanted to proceed, and started tracking the price on amazon. It is currently at $161 for the 225 model (the diamond in the rough for price/features imho), and if the past is any indication, will jump back up pretty soon. I happily snagged one at $180.

A quick summary as to why I like it, maybe for someone less in the know than myself:
-this energybar will power my ARB 50qt for almost 24 hours (empty, and without precooling it...)
-lifepo4 batteries won't off gas and they won't suffer from complete depletion
-lightweight and smaller form factor than your average automotive battery
-built in inverter and usb ports are icing on the cake
-the 12v charger from the same company provides a convenient on the road recharging solution


Over the past couple years since I have joined, I have spent many any hour reading the countless expo threads on similar topics, so a big thank you to all of those who have contributed to my education here!


https://www.amazon.com/Aspect-Solar...e=UTF8&redirect=true&ref_=s9_acsd_al_bw_c_x_3

 

[Whito123]

Thanks, just snagged one.

 

[zelatore]

I see they rate it in watt/hours, not amp/hours like a traditional battery. 225 w/h would be approximately (12v*18.75a=225w/h) 18.75 a/h. Since this is a LifePo4 I realize you can run that down to 0 where you can't discharge a typical flooded or AGM past 50% (70% would be better) but is that really enough to run your fridge from nothing for 24 hrs?

I'm guessing the fridge probably draws around 7 amps when running. Let's say it runs for 2 hours straight to get down to temp so that's 14 a/h right there. That only gives us 4.75 w/h to run the fridge for the remaining 22 hours at whatever duty cycle the outside temp demands.

For reference, a typical group 31 100 a/h battery would be approximately (12v*100a=1200w/h) 1200 w/h. If we say half of that is usable we're still comparing 600 to 225.

Am I doing the math wrong? I hope it works for you and look forward to the tech getting more affordable as the small size and weight is appealing but I've never looked at them as affordable replacements for traditional batteries. At least not yet.

 

[surly]

Ours was a dud. Sent the power bar and solar panel back.
IMHO it's not up to running a fridge and the 12v plug was loose no matter what I plugged in there.
Replaced it with an Arkpak.

 

[Chris Boyd]

I have a yellow top AGM and with a full load of groceries and moderate ambient in the truck, I can *just* make 24 hrs... And that battery is 85Ah. Can't see how you'd make it with only 18 Ah.

This past weekend I camped for4 days and with 130watt of solar charging the battery during the day in mostly sunny conditions, I didn't have to run the vehicle at all. The ambient was a bit hotter at 90 so the interior temps of the vehicle got into the high 90s during the day and 70s at night. With this the battery was down around 25% in the morning. This is likely because the solar couldn't really get the battery to 100% during the day because of the heat loads and cycle times during the hotter ambient.

All that to say, you can't just say it's X Amps per hour... Depends on the fridge load and the ambient temps of the air around it.

For this, I can't imagine you'd be able to run it on a battery this small. The ArkPak sounds like the batter route.

 

[teethless]

Great to hear the first hand experience Surly! Sounds disappointing...hope my unit fares better.

Yeah, this power solution may not be for everyone thats for sure. A little about why it works for me: Since my fridge never lives in my vehicle(s), except when on a trip, I liked the idea of an ultra portable power solution. (Even with a modest AH supply) After looking at all the excellent options, Arkpak, etc, I started thinking smaller and lighter, and ended up trying out a cheezy Costco "jumper pack" with a 12v receptacle on it to experiment. Probably an 8AH battery in that thing IIRC... even after traveling with it for weeks, it surprisingly met our needs, but never made it through the hot summers night. So we'd maayybe suffer a couple degrees rise in fridge temp, and the inconvenience of having to "swap plugs" while setting up or tearing down camp, but as a proof of concept that a similar approach would work for us, I was satisfied.

When my fridge gets used, it is pre-chilled inside then filled with pre-chilled consumables, before plugging into my vehicles 12v socket. Then after driving some where and setting up camp (rarely in a location for more than one night before driving again) I would plug in to the aux battery. So I was happy to see this energy bar 225 would power my fridge for at least my modest requirement of it (12-18 hours?) Maybe the battery goes flat during that time? I'm not worried about it. Just want it to act as a buffer to my starting battery more than anything, and still give me the option to run a fan or maybe some led lighting from time to time.

If you need more juice, yes, Arkpak or Luna seem worth it! So does going the route of the "$50 dual battery thread."

For number crunching: According to ARB's website, the 50qt's seem to draw an intermittent 1.35 amps per hour or 0.7-2.3 amps per hour. @Zelatore: Your math skills seem strong, although making a few assumptions there. IIRC, my fridge will reach temp well under 2 hours...I wanna say my fridge is "idling" within the first hour... I agree, the tech may not be quite there yet ($ to AH benefit) to replace conventional batts. I sure am excited to see what power solutions we're all discussing within the next 5-10 years!

YMMV and all that!